Treasurer says freeway upgrade needed as debt soars

The State Government concedes a major freeway upgrade will push the state further into debt, but says it is necessary to ease traffic congestion.

The government will spend an additional $440 million on a number of projects including a six kilometre extension of the Mitchell Freeway from Burns Beach Road to Hester Avenue, to be completed in four years.

A problem intersection at Reid Highway and Malaga Drive will also undergo a major upgrade.

The opposition says the project is extravagant and will put the state's triple-A credit rating at risk.

The Transport Minister and Treasurer, Troy Buswell, says it is needed to keep pace with the state's rapidly growing population.

"We're happy to borrow money to invest in this sort of infrastructure today because to wait five or ten years would quite simply be unacceptable," he said.

"In that shorter term, short to medium term, state debt will continue to increase, simply because we are investing in the infrastructure that a growing state and a transforming state requires."